SoylentNews is people
SoylentNews
Submitted via IRC for SoyCow4408
Ceramic materials are used in nuclear, chemical and electrical power generation industries because of their ability to withstand extreme environments. However, at high temperatures, ceramics are susceptible to thermal-shock fractures caused by rapid temperature-changing events, such as cold water droplet contact with hot surfaces. In a novel interdisciplinary approach, engineers report the use of a cheap, simple, water-repelling coating to prevent thermal shock in ceramics.
Source: Improved thermal-shock resistance in industrial ceramics
This discussion has been archived.
No new comments can be posted.
Improved Thermal-Shock Resistance in Industrial Ceramics
|
Log In/Create an Account
| Top
| 17 comments
| Search Discussion
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
(1)
(1)
Tell a man there are 300 billion stars in the universe and he'll believe you.
Tell him a bench has wet paint on it and he'll have to touch to be sure.
(Score: 0) by Anonymous Coward on Friday August 24 2018, @12:58PM (5 children)
If you spit on a really hot surface it makes a really rank smell--I've always assumed it was the proteins in the saliva burning. Learned this when welding as a teenager, testing to see if a piece was cool enough to handle. Now I keep some water around in an old mug or something, dip my fingers and flick some drops on the hot part.
Mod me off topic if you want, but the summary and the link don't give many details about this new development. It involves nano particles on the surface that promote a vapor layer, avoiding direct liquid contact with the ceramic--no details of the composition or shapes.
(Score: 3, Informative) by RS3 on Friday August 24 2018, @01:41PM (4 children)
They're using the term "nano" a bit loosely, IMHO. You could say that spray paint on a car with aluminum flakes for the metallic look is nanoparticles.
But that aside, think of it more as both an insulator and water repellent for clothing, like ScotchGuard. When you drip water on a very hot surface, you notice it wets- adheres- to the surface but also instantly boils. This stuff stops the surface wetting, so the heat transfer is slower, IE, less thermal shock.
(Score: 0) by Anonymous Coward on Friday August 24 2018, @03:36PM
I wonder if the coating has the same high temperature capabilities as the base ceramic? Didn't get any sense of this in the summary or when reading at the link.
I realize the coating is not actually ScotchGuard or any organic coating, because that would evaporate or boil off long before the limiting temperatures of industrial ceramics.
(Score: 2) by DeathMonkey on Friday August 24 2018, @05:08PM (2 children)
They're using the term "nano" a bit loosely, IMHO. You could say that spray paint on a car with aluminum flakes for the metallic look is nanoparticles.
What do you mean? A nanoparticle [wikipedia.org] is just a particle that's between 1 and 100 nanometers in size. The delivery medium has nothing to do with it.
Aluminum flakes are bigger than 100 nanometers and Alumina [wikipedia.org] is smaller than 100 nanometers.
(Score: 2) by RS3 on Friday August 24 2018, @06:53PM
Okay, okay, you win, I give. I know the terms "nano", pico, femto, etc. https://en.wikipedia.org/wiki/Metric_prefix [wikipedia.org]
I see the word "nano" usually used in reference to something active, rather than a simple passive coating. I know it's colloquial, but language is ever evolving. OP was confused by the article and I just tried to help.
I know, -1 flamebait, offtopic, troll, whatever.
(Score: 2) by RS3 on Friday August 24 2018, @06:56PM
PS: I wish I could respond privately to the one poster. I often write in context, and others, such as yourself, have broader knowledge and understanding. In other words, when I try to explain something to someone, I try to understand and adapt to that person. But I'm learning how this works...
(Score: 2) by VLM on Friday August 24 2018, @05:31PM (10 children)
And in a completely on-topic example of how it'll work when deployed in the real world, Pyrex(tm) used to mean american made borosilicate glass up to the turn of the century; you could thermally abuse the hell out of it in the kitchen and it wouldn't break, not Pyrex(tm) was sold to China and is cheap shitty soda-lime glass that shatters if you breathe on it while its hot (well, maybe not that bad, but pretty damn bad).
So... pre turn of the century "glass" cookware is thermally indestructible but the same trademark post turn of the century means its crap that'll shatter sometimes quite violently.
Its not an abstract problem... you want to baste some chicken breasts with sauce from the fridge, you'll get a shattered mess of glass with post turn of the century Pyrex(tm) and pre turn of the century Pyrex(tm) will laugh at that thermal load.
So bringing it around, if you think this means spark plug insulators will be immortal, or whatever, well, yeah, if American made for a couple years, but it'll be China made crap in no time. Kinda like how you can buy genuine titanium coated HSS or cobalt drills made in the USA for about three times the cost of similar appearing carbon steel with gold spray paint drills from China. Obviously the walmart drills "unwind" themselves if used and the paint rubs off on the first hole ruining your work, while the real cobalt TiN coated made in the USA drill lasts forever, but ...
(Score: 0) by Anonymous Coward on Friday August 24 2018, @06:55PM (9 children)
I have seen this before and am curious: why do Americans assume that borosilicate glass can't be bought anymore just because it isn't called Pyrex? There's plenty of true borosilicate glass under other brands.
(Score: 0) by Anonymous Coward on Friday August 24 2018, @08:50PM
Can't handle the dynamics of a changing free market.
(Score: 0) by Anonymous Coward on Friday August 24 2018, @09:58PM (5 children)
Well, is there an easy test to see if glass cookware is made of the good stuff or some lower quality substitute?
As I understand it, the reason original Pyrex(tm) is good is because it has near zero thermal coefficient of expansion over the working temperature range. Thus thermal shock does not cause mechanical size changes. Same for the glass or ceramic used to make "counter that cooks" range tops.
Does the good stuff have a different index of refraction that could be measured easily? Maybe some other easily measured property?
(Score: 1) by khallow on Saturday August 25 2018, @03:49AM (2 children)
(Score: 0) by Anonymous Coward on Saturday August 25 2018, @02:14PM (1 child)
Wooosh -- the idea is to verify the type of glass before buying it.
(Score: 1) by khallow on Sunday August 26 2018, @03:26AM
(Score: 3, Informative) by deimtee on Saturday August 25 2018, @09:19AM
The old good pyrex has a slight yellowish tinge to it. The new crap pyrex is blueish.
Not sure if that is universal, and whether whoever is currently fucking the pyrex name is likely to wake up and start making yellow shit to make a few more dollars.
No problem is insoluble, but at Ksp = 2.943×10−25 Mercury Sulphide comes close.
(Score: 0) by Anonymous Coward on Saturday August 25 2018, @12:08PM
The easy test is read the packaging and look for the word borosilicate.
(Score: 1, Informative) by Anonymous Coward on Saturday August 25 2018, @05:28AM (1 child)
Two things:
1. the problem is mostly that the "old pyrex" of value is now lost among the new
2. nobody in north america brands home cooking glass as borosilicate. Yes, for installed glass cooking surfaces, and for chemists. But not houseware glass. So there's no way to buy it /reliably/ which is the point of the parent complaint.
(Score: 1, Informative) by Anonymous Coward on Saturday August 25 2018, @11:03AM
There's life outside north america. I have used SIMAX (Czech) and Boral (German) glassware and they have never failed me when handling heat/cold (only mechanically due to my clumsiness).
https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=simax [amazon.com]